First-principles density functional theory (DFT) calculations were performed using the Quantum Espresso package (QE) [1]}. We used the generalized gradient approximation with the Perdew-Burke-Ernzerhof parameterization [2]} together with projector-augmented wave pseudopotentials generated by Dal Corso [3]}. In all cases, we used an energy cutoff of 90 Ry with a Methfessel-Paxton smearing [4]} of 0.02 Ry. The structural relaxation was done with a 18x18x2 grid neglecting spin-orbit coupling (SOC) and was stopped when pressures are below 0.01 kBar. The bands and the Fermi surface where computed with SOC and 18x18x12 and 25x25x16 respectively.
